Thermal therapy is the practice of applying heat and/or cold to tissue to reduce swelling/inflamation, to decrease pain, promote healing, increase blood flow, alleviate aches, calm stress points, and/or just for general relaxation. The thermal effect (i.e., heat or cold) can be accomplished by the heating or cooling effect of a therapy-providing fluid (e.g., water, oil) in thermal contact with the relevant tissue. To this end, a tissue-interacting device (containing the therapy-providing fluid) can be strapped or otherwise held in contact with the relevant areas of the therapy-receiving person's body.